Diaphragm type regulator valves are used in applications that include, for example, the delivery of natural gas. Such valves can be configured with a spring biasing the diaphragm against resistance provided by pressure in a chamber on the other side of the diaphragm. Fluid connections between the chamber and the downstream side of the regulator valve cause pressure in the chamber to reflect pressure on the downstream side of the regulator valve. Thus, changes in pressure on the downstream side of the regulator valve cause movement of the diaphragm that, through mechanical linkages, can cause valve disc movement.
L-shaped levers can be used as part of these mechanical linkages. Such levers can be configured to provide a particular ratio between the amount of diaphragm movement and the amount of valve disc movement. This ratio and the forces applied are constant regardless of whether the valve is opening or closing and regardless of the position of the valve disc.